function postcall( url, params, target){
    var tempForm = document.createElement("form");
    tempForm.action = url;
    tempForm.method = "post";
    tempForm.style.display="none"
    if(target) {
        tempForm.target = target;
    }
    for (var x in params) {
        var opt = document.createElement("input");
        opt.name = x;
        opt.value = params[x];
        tempForm.appendChild(opt);
    }
    var opt = document.createElement("input");
    opt.type = "submit";
    tempForm.appendChild(opt);
    document.body.appendChild(tempForm);
    tempForm.submit();
    document.body.removeChild(tempForm);
}